Overhead tns

[Nickj]

Hi guys,

Went to see a property today.

Just wanted to clarify the supply type with you.

I believe it's overhead tns but others have told customer it's overhead tt.

Could you share your thoughts?

There are 3 incoming cables that come from above the house and run down into the suppliers equipment.

As they are supplying the earth I believe it is overhead tns

Picture attached as a picture paints a thousand words

View attachment 35751

 

[Midwest]

Difficult to tell from that blurred picture

The only way to be sure is ask the DNO, they might even change their supply cable and convert to TN-C-S?

 

[Nickj]

Dno wouldn't comment. They said they can provide an upgrade to pme at cost to the customer.

If it's overhead tns as I suspect then I see no reason to force additional cost to customer to change to pme...

The dno definitely are supplying 3 seperate cables to the house. Whether they have them as tns or tncs is impossible for me to say really?

The fact they are providing 3 wires rules out overhead tt? There is definitely no rod at the property as the only means of earthing is throigh the dno supplied cable...

Grrr

 

[LeeH]

Is the Ze high? Upfront RCD present?

 

[Nickj]

It was only a brief look and I didn't take a Ze as I'd have needed a ladder.

No up front rcd, I had a Zs on sockets of 0.51.

Overall I'm airing on side of tns or tncs and ruling out overhead tt (based on them providing 3 cables).

Dno say they have no idea and we're just interested in charging to change to pme

 

[Wilko]

Hi - agree 3 cables and looks like TNS, perhaps check Ze and if between 0.35 and 0.8 then most likely TNS ?
Edit : tooo slow typing, with 0.51 Ze it ain't TT and afaik it's too high for their own stated target for PME.

 

[Toneyz]

Dno wouldn't comment. They said they can provide an upgrade to pme at cost to the customer.

If it's overhead tns as I suspect then I see no reason to force additional cost to customer to change to pme...

The dno definitely are supplying 3 seperate cables to the house. Whether they have them as tns or tncs is impossible for me to say really?

The fact they are providing 3 wires rules out overhead tt? There is definitely no rod at the property as the only means of earthing is throigh the dno supplied cable...

Grrr

Have you done a loop test L-E & L-N this gives usually a good indication

 

[LeeH]

i would have thought TNS to.

Have a look at the poles, some of them in my village you can see every few poles dogged down to Tera Firma. But it's probably not PME if the DNO is trying to sell you a conversion.

Edit: Wilko's got it in the bag.

 

[Nickj]

Hi wilko,

0.51 is the rfc Zs not the Ze. Was unable to take a Ze due to lack of ladder. Will take that when there next.

As dno is supplying 3 cables and as they are trying to sell pme I'm going to go with tns.

Dno are really not as helpful as they should be!

 

[buzzlightyear]

TT SYSTEM . NEXT TIME YOU TAKE PIC, STAND BACK A BIT DAVID BAILEY

 

[Nickj]

Hi buzzlightyear,

On what grounds do you think it's TT?

 

[buzzlightyear]

where is the dno coming in from .

 

[Nickj]

The roof of the house with 3 cables. All properties on the street appear to be the same, 3 cables coming from the roof of house down the exterior wall and into the dno equipment as per the picture

 

[Rpa07]

TT SYSTEM . NEXT TIME YOU TAKE PIC, STAND BACK A BIT DAVID BAILEY

That's a twin and Earth Buzz, optical illusion doesn't help but Nickj says 3 coming in, he's a spark - sparks can count past 3 so he is to be believed.

 

[buzzlightyear]

sorry can not make out the picture . was he using a old brownie camera.
with all the bell a whistle phones around . are you going back to the property .

 

[7029 dave]

Looks very much like TNS to me, with that ZE to

 

[buzzlightyear]

I still say TT system .

 

[mattg4321]

What makes you think TT?

 

[Midwest]

Assume makes an --- out of U and Me.

 

[sparkdog]

That there aint no TT.